docs: def connectivity_mapping(self):
          """
          :return: This property returns a mapping of the interdepencies between
              variables. This is essentially the dict representation of a
              connectivity graph, because working with this dict results in
              cleaner code. Treats variables and parameters on the same footing.
          """
          connectivity = {}
          for var, expr in self.items():
              vars, params = seperate_symbols(expr)
              connectivity[var] = set(vars + params)
          return connectivity